I traded my Boker Specialist, mostly because I didn't carry it, due to the lack of a guard. Kind of strange, because I carry my R.J. Martin Kozuka daily despite the lack of a guard. The Kozuka just feel more secure to me.
The Boker does have a slight dip in the handle, which is supposedly an index for your finger, but I found it to be totally non-functional for a guard. If Boker would make one with a guard, I would buy many of them, mostly because the sheath systemis awesome.
On the plus side, if you do need to stab with your Specialist, you can press the butt of the knife into your palm. It seems to work well for this technique.
marco